The present invention is in the field of medical devices. More particularly it relates to methods and devices for measuring an analyte present in a biological system.
Self-monitoring of blood glucose is a critical part of managing diabetes. However, present procedures for obtaining such information are invasive, painful and provide only periodic measurements. Standard methods of measuring involve the use of painful and cumbersome finger stick blood tests. Thus, development of a painless and automatic approach would represent a significant improvement in the quality of life for people with diabetes. Further, a tight glucose control regimen, which uses frequent glucose measurements to guide the administration of insulin or oral hypoglycemic agents, leads to a substantial decrease in the long-term complications of diabetes. See, Diabetes Control and Complication Trial Research Group (1993) N. Engl. J. Med. 329:997-1036.
In one aspect, the invention includes a monitoring system for frequently measuring an analyte present in a biological system, said monitoring system comprising,
(a) a first component comprising
(i) a transdermal or transmucosal sampling mechanism for extracting the analyte from the biological system, wherein said sampling mechanism is adapted for extracting the analyte across a skin or mucosal surface of said biological system;
(ii) sensing mechanism in operative contact with the analyte extracted by the sampling mechanism, wherein said sensing mechanism obtains a signal from the extracted analyte and said signal is specifically related to the analyte; and
(iii) first mechanism for providing operative communication with a second component of the monitoring system; and
(b) a second component comprising
(i) a user interface; and
(ii) second mechanism for providing operative communication with the first component.
In certain embodiments, the sampling mechanism is iontophoresis, electroosmosis, sonophoresis, microdialysis, suction and passive diffusion. In certain embodiments, the first component further comprises a computing mechanism that converts the signal from the extracted analyte to an output indicative of the amount of analyte extracted by the sampling mechanism. The output can be communicated to the second component for display. Further, in other embodiments, the second component receives the signal from the first component, wherein the second component further comprises a computing mechanism that converts the signal from the extracted analyte to an output indicative of the amount of analyte extracted by the sampling mechanism and wherein the second component displays said output. The first and second mechanisms for providing operative communication can comprise a wire-like connection, wireless communication technology or a combination of wire-like and wireless technologies. Wireless communication technology can employ, for example electromagnetic waves (e.g, low frequency electromagnetic waves in a frequency range of about 1 Hz. to about 1 Mega Hz; medium frequency electromagnetic waves in a frequency range of about 1 Mega Hz. to about 500 Mega Hz or high frequency electromagnetic waves in a frequency range of about 500 Mega Hz. to about 5 Giga Hz); capacitance coupling between the biological system and the biological system""s environment; inductive coupling; infrared coupling; high frequency acoustic energy or combinations thereof. In still further embodiments, the second component of the monitoring system relays command signals to the first component, for example, signals to control operation of the sensing mechanism or signals to control operation of the sampling mechanism. In certain embodiments, the second component can store analyte-related data. In yet another embodiments, the analyte is glucose. In certain embodiments, the biological system is a mammal, for example a human.
In yet another aspect of the invention, the monitoring system as described herein that further comprises
(c) a third component comprising
(i) a delivery device; and
(ii) a third mechanism for providing operative communication with the first and second components. The delivery device can be implanted in the biological system (e.g., subcutaneously) or, alternatively, can be external to the biological system. In certain embodiments, the analyte is glucose and the delivery device comprises an insulin pump. In certain embodiments, the communication between first and second components and the third component is wireless, for example, one or more of the wireless technologies described herein.
In yet another aspect, the invention includes a monitoring system described herein that further comprises
(c) a third component comprising
(i) a modem or personal computer; and
(ii) a third mechanism for providing operative communication with the first and second components. In certain embodiments, the modem or personal computer is remote from the biological system and the communication between the first and second components and the third component is wireless. The modem or personal computer may also be operably linked to a wide area network (WAN), for example the internet. In certain embodiments, the analyte is glucose.
These and other embodiments of the present invention will readily occur to those of ordinary skill in the art in view of the disclosure herein.